g(x) - f(x) means subtracting the value of function f(x) from the value of function g(x). The steps of the solution are listed below:
[tex]g(x)= 3^{x}-9 \\ \\
f(x)=5x-1 \\ \\
g(x)-f(x)= 3^{x}-9-(5x-1) \\ \\
g(x)-f(x)=3^{x}-9-5x+1 \\ \\
g(x)-f(x)=3^{x}-5x-8[/tex]
